This invention relates to a stay for pivotally supporting the sprocket shaft of the transmission unit in a chain saw.
In the conventional electric-powered chain saws of the type in which the motor rotation is reduced in speed by using a spur gear or helical gear train, there are usually provided a pair of bearing units for pivotally supporting the sprocket shaft of the final stage, so that very troublesome works were involved, such as removing one of the chain saw covers, many bolts and other parts, for making repairs, setting, replacement and other works on the saw chain. For avoiding such troublesomeness, it has been attempted to adopt a cantilever support for the sprocket shaft. However, in order to keep the shaft proof against bending or break under the tension load exerted to the saw chain, it was required to provide the shaft with sufficient thickness, necessarily resulting in enlarged size and increased weight of the transmission mechanism.
The present invention is intended to eliminate such defects inherent to the conventional chain saws.